The objective of this research is the development of new or improved techniques of applying cariostatic substances to the mouth that will result in improved access and prolonged retention around caries-prone areas and the evaluation of the reliability and validity of techniques used to assess the effectiveness of the new procedures. The methods developed must be shown by chemical or other means to lead to a significant retention; they must be non-toxic and suitable for use in the human mouth; they must be inexpensive and possible to produce on a large scale; and they must be easily applied and in a form that ultimately can be made available to the general public.